There is talk the Roswell greys were really Japanese soldiers in "advanced" sky technology. They built the machines too small for westerners to fit into. Something in their training involved losing a finger if the test was failed. The craft could only be operated by a four fingered person. They shaved all their body hair. It's interesting. Douglas Dietricht destroyed files for the military and it was something he came across. Not to say their isn't "alien" craft, but the story is plausible.